It is well known that \(\rho _{inf}(\sim \,10^{60}\,{\rm Gev}^4)\gg \,\rho _{RD}\,(\sim \,{\rm MeV}^4)\,>\,\rho _{MD}\,(\sim \,{\rm eV}^4)\) , where \(\rho _{inf},\,\rho _{RD},\,\rho _{MD}\)  are the proper energy densities of inflationary, RD, and MD phases of the Universe, respectively [1]} .
Now using \(\rho _{inf},\,\rho _{RD},\,\rho _{MD}\)  and (\(\omega =\,-1,\, 1/3, 2/3\) ) for inflationary, RD and MD phases, respectively, one can perceive that the curvature scalar corresponding to the inflationary epoch is much larger than the curvature scalar for the RD and MD eras.
